I would go with stronger or 'a larger force' than sliding friction. either way, the reasoning is that friction is caused by the force earth is exerting on an object. when this object is in motion, there are multiple vectors that this force can be broken down into, and also momentum and inertia come in to play.
Let us first calculate the average speed of David,
Av speed = Distance traveled/ Time taken
We have, distance = 70 miles
Time = hours = 1.75 hours
Av speed =
= 40 miles/hour
Another 120 miles will be traveled in time, t = 120/40 = 3 hours
G
has the SI units
m
3
k
g
⋅
s
2
Answer:
-0.9 m/s²
Explanation:
t = Time taken by the hockey puck = 7 seconds
u = Initial velocity of the hockey puck = 13 m/s
v = Final velocity of the hockey puck = 6.7 m/s
a = Acceleration of the hockey puck
Equation of motion
The acceleration of the hockey puck in the seven seconds is -0.9 m/s²
The acceleration due to gravity is not needed to find the acceleration of the puck.