Question 1

A 1800 kg car moving at 20 m/s hits an initially uncompressed spring with a spring constant of 2.0 $\times$ 106 N/m.The maximum compression of the spring is

Accepted Answer

A)  0.40 m. 
B)  0.60 m. 
C)  0.80 m. 
D)  1.0 m. 
E)  1.2 m. 
A)  0.40 m. 
B)  0.60 m. 
C)  0.80 m. 
D)  1.0 m. 
E)  1.2 m.

Question 2

A 20.0 N force is applied at an angle of 40.0 degrees above the horizontal to a 4.00 kg box.The box moves a horizontal distance of 4.00 meters.Friction is negligible.The work done by the 20.0 N force is

Accepted Answer

A)  75.0 J. 
B)  61.3 J. 
C)  50.1 J. 
D)  46.3 J. 
E)  40.5 J. 
A)  75.0 J. 
B)  61.3 J. 
C)  50.1 J. 
D)  46.3 J. 
E)  40.5 J.

Question 3

A 2.00 kg pendulum bob on a string 1.50 m long,is released with a velocity of 3.00 m/s when the support string makes an angle of 45.0 degrees with the vertical.What is the tension in the string at the bottom of the swing?

Accepted Answer

A)  53.5 N 
B)  49.8 N 
C)  43.1 N 
D)  37.5 N 
E)  30.2 N 
A)  53.5 N 
B)  49.8 N 
C)  43.1 N 
D)  37.5 N 
E)  30.2 N

Question 4

An asteroid,of radius 2.1 km,is observed to have an escape speed equal to a typical person's speed attained by jumping off , 3.0 m/s.What is its mass?

Accepted Answer

A)  4.2 $\times$ 1014 kg 
B)  2.8 $\times$ 1014 kg 
C)  5.7 $\times$ 1014 kg 
D)  0.5 $\times$ 1014 kg 
E)  1.4 $\times$ 1014 kg 
A)  4.2 $\times$ 1014 kg 
B)  2.8 $\times$ 1014 kg 
C)  5.7 $\times$ 1014 kg 
D)  0.5 $\times$ 1014 kg 
E)  1.4 $\times$ 1014 kg

Question 5

A 5.00 gram bullet has a velocity of 300 m/s.It strikes a block of wood and penetrates to a distance of 2.00 cm.The average force of the block of wood on the bullet is

Accepted Answer

A)  9,340 N. 
B)  11,250 N. 
C)  15,200 N. 
D)  19,500 N. 
E)  21,400 N. 
A)  9,340 N. 
B)  11,250 N. 
C)  15,200 N. 
D)  19,500 N. 
E)  21,400 N.

Question 6

A 2500 kg car accelerates up to a velocity of 30.0 m/s in 8.00 seconds.The work done by the engine to accelerate the car is

Accepted Answer

A)  3.10 $\times$ 106 J. 
B)  2.56 $\times$ 106 J. 
C)  2.01 $\times$ 106 J. 
D)  1.85 $\times$ 106 J. 
E)  1.13 $\times$ 106 J. 
A)  3.10 $\times$ 106 J. 
B)  2.56 $\times$ 106 J. 
C)  2.01 $\times$ 106 J. 
D)  1.85 $\times$ 106 J. 
E)  1.13 $\times$ 106 J.

Question 7

A 20.0 kg box slides up a 12.0 m long incline at an angle of 30.0 degrees with the horizontal.A force of 150 N is applied to the box to pull it up the incline.The applied force makes an angle of 10.0 degrees to the incline and above the incline.If the incline has a coefficient of kinetic friction of 0.100,then the increase in the kinetic energy of the box is

Accepted Answer

A)  424 J. 
B)  395 J. 
C)  344 J. 
D)  297 J. 
E)  250 J. 
A)  424 J. 
B)  395 J. 
C)  344 J. 
D)  297 J. 
E)  250 J.

Question 8

A blob of clay,mass M,is propelled upward from a spring that is initially compressed by an amount d.If,upon its release,the clay reaches an ultimate height of h above the unstretched spring's end,what is the spring constant k?

Accepted Answer

A)  kd2/(mg) 
B)  kd2/(2mg)- d 
C)  kd2/(mg)-d 
D)  kd2/(2mg) 
A)  kd2/(mg) 
B)  kd2/(2mg)- d 
C)  kd2/(mg)-d 
D)  kd2/(2mg)

Question 9

In order to conserve fuel,you modify your car by removing 100 kg of excess weight.How much energy is saved each time you accelerate from 0 to 100 km/hr (62 mph)?

Accepted Answer

A)  2.86 $\times$ 102 J 
B)  2.86 $\times$ 104 J 
C)  3.86 $\times$ 104 J 
D)  3.86 $\times$ 102 J 
A)  2.86 $\times$ 102 J 
B)  2.86 $\times$ 104 J 
C)  3.86 $\times$ 104 J 
D)  3.86 $\times$ 102 J

Question 10

The explosion in a cannon exerts an average force of 30,000 N for 2.00 meters.The velocity of a 2.00 kg projectile shot from the cannon is

Accepted Answer

A)  198 m/s. 
B)  245 m/s. 
C)  302 m/s. 
D)  354 m/s. 
E)  412 m/s. 
A)  198 m/s. 
B)  245 m/s. 
C)  302 m/s. 
D)  354 m/s. 
E)  412 m/s.

Question 11

A 120 N horizontal force is applied to a 4.00 kg box.The box moves a horizontal distance of 8.00 meters.The change in the kinetic energy of the box is

Accepted Answer

A)  960 J. 
B)  875 J. 
C)  821 J. 
D)  765 J. 
E)  633 J. 
A)  960 J. 
B)  875 J. 
C)  821 J. 
D)  765 J. 
E)  633 J.

Question 12

A 75 kg road bicycle racer rides down the highway from Pike's peak.During one stretch of the ride,he descends 150 m while accelerating from 35 km/hr to 55 km/hr.Assuming rolling friction to be negligible,what is the average power supplied by the Earth through the gravitational force during the time (12.5 s)?

Accepted Answer

A)  700 W 
B)  5.4 kW 
C)  9.1 kW 
D)  417 W 
A)  700 W 
B)  5.4 kW 
C)  9.1 kW 
D)  417 W

Question 13

A 20.0 kg box slides down a 12.0 m long incline at an angle of 3.0 degrees with the horizontal.A force of 50.0 N is applied to the box to try to pull it up the incline.The applied force makes an angle of 0.00 degrees to the incline.If the incline has a coefficient of kinetic friction of 0.100,then the increase in the kinetic energy of the box is

Accepted Answer

A)  300 J. 
B)  372 J. 
C)  410 J. 
D)  455 J. 
E)  525 J. 
A)  300 J. 
B)  372 J. 
C)  410 J. 
D)  455 J. 
E)  525 J.

Question 14

A spring-powered dart gun is un-stretched and has a spring constant 150 N/m.The spring is compressed by 8.00 cm and a 5.00 gram projectile is placed in the gun.The maximum height of the projectile when it is shot at an angle of 30.0 degrees above the horizontal from the gun is

Accepted Answer

A)  5.03 m. 
B)  4.24 m. 
C)  3.90 m. 
D)  3.20 m. 
E)  2.45 m. 
A)  5.03 m. 
B)  4.24 m. 
C)  3.90 m. 
D)  3.20 m. 
E)  2.45 m.

Question 15

A ski lift carries passengers up a 150 m high slope at the rate of one chair every 30.0 seconds.If the chair will hold two passengers with a total mass of 190 kg,then the power of the engine that powers the ski lift is

Accepted Answer

A)  6.96 kW. 
B)  7.83 kW. 
C)  8.75 kW. 
D)  9.31 kW. 
E)  9.90 kW. 
A)  6.96 kW. 
B)  7.83 kW. 
C)  8.75 kW. 
D)  9.31 kW. 
E)  9.90 kW.

Question 16

A 2.00 kg pendulum bob on a string 1.50 m long,is released with a velocity of 4.00 m/s when the support string makes an angle of 30.0 degrees with the vertical.What is the angle with the vertical the bob makes at the highest point of its motion?

Accepted Answer

A)  85.3 degrees 
B)  71.2 degrees 
C)  60.3 degrees 
D)  56.7 degrees 
E)  45.0 degrees 
A)  85.3 degrees 
B)  71.2 degrees 
C)  60.3 degrees 
D)  56.7 degrees 
E)  45.0 degrees

Question 17

A 20.0 kg box slides up a 12.0 m long incline at an angle of 30.0 degrees with the horizontal.A force of 150 N is applied to the box to pull it up the incline.The applied force makes an angle of 10.0 degrees to the incline.What is the change in gravitational potential energy,in Joules?

Accepted Answer

A)  2,570 
B)  2,350 
C)  1,450 
D)  1,180 
E)  945 
A)  2,570 
B)  2,350 
C)  1,450 
D)  1,180 
E)  945

Question 18

A 20.0 kg box slides down a 12.0 m long incline at an angle of 30.0 degrees with the horizontal.A force of 50.0 N is applied to the box in the upward direction to try to pull it up the incline.The applied force makes an angle of 10.0 degrees to the incline.If the incline has a coefficient of kinetic friction of 0.00,then the increase in the kinetic energy of the box is

Accepted Answer

A)  420 J. 
B)  475 J. 
C)  521 J. 
D)  585 J. 
E)  620 J. 
A)  420 J. 
B)  475 J. 
C)  521 J. 
D)  585 J. 
E)  620 J.

Question 19

A 30.00 kg box slides up a 12.00 meters long incline at an angle of 30.00 degrees above the horizontal.Friction is negligible.The change in gravitational potential energy is

Accepted Answer

A)  2110 J. 
B)  1467 J. 
C)  1080 J. 
D)  1764 J. 
E)  760.0 J. 
A)  2110 J. 
B)  1467 J. 
C)  1080 J. 
D)  1764 J. 
E)  760.0 J.

Question 20

A spring with a spring constant of 8.0 N/m is compressed to 20 cm.If the spring is uncompressed initially,then the work done is

Accepted Answer

A)  0.12 J. 
B)  0.16 J. 
C)  0.19 J. 
D)  0.22 J. 
E)  0.26 J. 
A)  0.12 J. 
B)  0.16 J. 
C)  0.19 J. 
D)  0.22 J. 
E)  0.26 J.

Exam 6: Conservation of Energy

A 1800 kg car moving at 20 m/s hits an initially uncompressed spring with a spring constant of 2.0 ×\times× 106 N/m.The maximum compression of the spring is

A 20.0 N force is applied at an angle of 40.0 degrees above the horizontal to a 4.00 kg box.The box moves a horizontal distance of 4.00 meters.Friction is negligible.The work done by the 20.0 N force is

A 2.00 kg pendulum bob on a string 1.50 m long,is released with a velocity of 3.00 m/s when the support string makes an angle of 45.0 degrees with the vertical.What is the tension in the string at the bottom of the swing?

An asteroid,of radius 2.1 km,is observed to have an escape speed equal to a typical person's speed attained by jumping off , 3.0 m/s.What is its mass?

A 5.00 gram bullet has a velocity of 300 m/s.It strikes a block of wood and penetrates to a distance of 2.00 cm.The average force of the block of wood on the bullet is

A 2500 kg car accelerates up to a velocity of 30.0 m/s in 8.00 seconds.The work done by the engine to accelerate the car is

A blob of clay,mass M,is propelled upward from a spring that is initially compressed by an amount d.If,upon its release,the clay reaches an ultimate height of h above the unstretched spring's end,what is the spring constant k?

In order to conserve fuel,you modify your car by removing 100 kg of excess weight.How much energy is saved each time you accelerate from 0 to 100 km/hr (62 mph)?

The explosion in a cannon exerts an average force of 30,000 N for 2.00 meters.The velocity of a 2.00 kg projectile shot from the cannon is

A 120 N horizontal force is applied to a 4.00 kg box.The box moves a horizontal distance of 8.00 meters.The change in the kinetic energy of the box is

A spring-powered dart gun is un-stretched and has a spring constant 150 N/m.The spring is compressed by 8.00 cm and a 5.00 gram projectile is placed in the gun.The maximum height of the projectile when it is shot at an angle of 30.0 degrees above the horizontal from the gun is

A ski lift carries passengers up a 150 m high slope at the rate of one chair every 30.0 seconds.If the chair will hold two passengers with a total mass of 190 kg,then the power of the engine that powers the ski lift is

A 2.00 kg pendulum bob on a string 1.50 m long,is released with a velocity of 4.00 m/s when the support string makes an angle of 30.0 degrees with the vertical.What is the angle with the vertical the bob makes at the highest point of its motion?

A 20.0 kg box slides up a 12.0 m long incline at an angle of 30.0 degrees with the horizontal.A force of 150 N is applied to the box to pull it up the incline.The applied force makes an angle of 10.0 degrees to the incline.What is the change in gravitational potential energy,in Joules?

A 30.00 kg box slides up a 12.00 meters long incline at an angle of 30.00 degrees above the horizontal.Friction is negligible.The change in gravitational potential energy is

A spring with a spring constant of 8.0 N/m is compressed to 20 cm.If the spring is uncompressed initially,then the work done is

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A 1800 kg car moving at 20 m/s hits an initially uncompressed spring with a spring constant of 2.0 $\times$ 10⁶ N/m.The maximum compression of the spring is