Answer:False
Explanation:
Work is being done on a body when it causes displacement of body on the application of force
When we pull the door by a force it causes zero displacements of the door. So we can say that work done on it is zero.
Thus the above-given statement is false
Answer:
(a). Their speed during that run is 10 m/s.
(b). Their velocity is 6.86 m/s
(c). The final position is at 8.91 m.
Explanation:
Given that,
A football player starts at the 40-yard line, and runs to the 25-yard line in 2 seconds.
Suppose, the distance between 40 yard line and 25 yard line is 20 yard.
(a). We need to calculate their speed during that run
Using formula of speed
Where. d = distance
t = time
Put the value into the formula
during that run
(b). We need to calculate their velocity
Using formula of speed
Put the value into the formula
Negative sign shows the direction of motion.
(c). If they kept running at that velocity for another 1.3 seconds,
We need to calculate the final position
Using formula of position
Put the value into the formula
Hence, (a). Their speed during that run is 10 m/s.
(b). Their velocity is 6.86 m/s
(c). The final position is at 8.91 m.