Answer:
735 J
Explanation:
Total height reached(displaced)=10x15 cm
= 10 x 15/100 m
= 1.5 m
Workdone = F.S (force x displacement)
Here, the boy is traveling against the gravitation force(=mg) , and traveled a height of 1.5m
Hence,
Workdone = 50 x 9.8 x 1.5 J
= 735 J
Answer:10.02 m/s
4.68 m/s
Explanation:
Given
height of building=4 m
time taken=1.5 s
(a)Let u be the initial velocity
using equation of motion



u=10.02 m/s
(b)Velocity of keys just before keys were caught




If the elevator falls from a height of 240 meters and Superguy is 1 km away, he will have 6.5 seconds to save Lois, which means that his average speed must be 150 meters per second.
<h3>What is the average speed?</h3>
The total distance traveled by an object divided by the total time taken is the average speed.
The average speed of an object indicates the pace at which it will traverse a distance. The metric unit of speed is the meter per second.
Given data:
Distance of super guy from the tower = 1.00 km
height(h)= 240 m
From the Newtons' second equation of motion:

Distance is the foundation as the product the velocity and time;
D=ut
u=d/t
u=1000/t
u=1000/6.5
u=150 m/sec
Hence, he will have 6.5 seconds to save Lois, which means that his average speed must be 150 meters per second.
To learn more about the average speed, refer to the link;
brainly.com/question/12322912
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