Answer:
10.8s
Explanation:
Given parameters:
Force on the car = 3250N
Distance = 35m
Power = 11375W
Unknown:
Time taken = ?
Solution:
To solve this problem;
Power is the rate at which work is done
Power =
Work done = force x distance = 3250 x 35 = 123200J
Now;
11375 =
11375t = 123200
t = 10.8s
Solution :
Given
Diameter of the roulette ball = 30 cm
The speed ball spun at the beginning = 150 rpm
The speed of the ball during a period of 5 seconds = 60 rpm
Therefore, change of speed in 5 seconds = 150 - 60
= 90 rpm
Therefore,
90 revolutions in 1 minute
or In 1 minute the ball revolves 90 times
i.e. 1 min = 90 rev
60 sec = 90 rev
1 sec = 90/ 60 rec
5 sec =
= 75 rev
Therefore, the ball made 75 revolutions during the 5 seconds.