Answer:
-63.6m/s
Step-by-step explanation:
Given parameters:
Initial velocity = 5m/s
Time of flight = 7s
Unknown:
Velocity of the eraser after 7s = ?
Solution:
To solve this problem, we have to use the right motion equation which is given below;
v = u - gt
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity = 9.8m/s²
t is the time taken;
Now insert the parameters and solve for v;
v = 5 - (9.8 x 7)
v = -63.6m/s