This question involves the concepts of average speed, distance, and time.
The average speed of the family is "2.5 mi/hr".
<h3>AVERAGE SPEED</h3>
The average speed is defined as the ratio of the total distance covered with the total time taken to cover it.

where,
- s = distance covered = 2.5 miles
- t = total time taken = 1 hour
- v = average speed = ?
Therefore,

v = 2.5 mi/hr
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Answer:
v = 29.4m/s
Explanation:
Since the ball is dropped at rest,
u = 0m/s
a = 9.81m/s²
Using
v = u + at
After 3 seconds,
v = 0 + (9.81)(3)
v = 29.4m/s
Answer:

Explanation:
This is a uniformly accelerated motion, so we can determine the deceleration of the car by using a suvat equation:

where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance covered
For the car in this problem,
u = 27.8 m/s
v = 0
s = 17 m
Solving for a, we find the acceleration:

Answer:
1750 Joules.
Explanation:
Work done = force * distance
= 7 * 250
= 1750 Joules.
Answer:

Explanation:
From the question we are told that:
Mass 
Speed 
Mass 
Speed 
Generally the equation for Magnitude of the Third piece is mathematically given by


Where



And


Therefore

