1.7.1a Energy stores and energy transfers

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Question 32

A builder drops a brick of mass $kg2.5\text{ kg}$ from a scaffold platform at a height of $m5.0\text{ m}$ above the ground. Take the acceleration of free fall to be $9.8\text{ m/s}^2$ .

(i) Calculate the change in gravitational potential energy of the brick when it is dropped.

[2]

(ii) Describe the energy transfers from the moment the brick is released until it is at rest on the ground.

[2]

Another builder on the site carries a bucket of mortar up a ladder to the platform. He climbs a vertical height of $m4.0\text{ m}$ in a time of $s8.0\text{ s}$ . His total weight, including the bucket, is $N600\text{ N}$ .

(i) Calculate the useful power which his muscles are producing.

[2]

(ii) In fact, his body is only $15%15\%$ efficient when climbing the ladder. Calculate the rate at which chemical energy stored in his body is being used.

[2]

A builder drops a brick of mass $kg2.5\text{ kg}$ from a scaffold platform at a height of $m5.0\text{ m}$ above the ground. Take the acceleration of free fall to be $9.8\text{ m/s}^2$ .

(i) Calculate the change in gravitational potential energy of the brick when it is dropped.

[2]

(ii) Describe the energy transfers from the moment the brick is released until it is at rest on the ground.

[2]

(i) Calculate the useful power which his muscles are producing.

(ii) In fact, his body is only $15%15\%$ efficient when climbing the ladder. Calculate the rate at which chemical energy stored in his body is being used.

[2]

1.7.1a Energy stores and energy transfers

Question 32

Markscheme

1.7.1a Energy stores and energy transfers

Question 32

Markscheme

1.7.1a Energy stores and energy transfers

Question 32

1.7.1a Energy stores and energy transfers Questions

1.7.1a Energy stores and energy transfers

Question 32

1.7.1a Energy stores and energy transfers Questions