Answer:
B) 20N.s is the correct answer
Explanation:
The formula for the impulse is given as:
Impulse = change in momentum
Impulse = mass × change in speed
Impulse = m × ΔV
Given:
initial speed = 40m/s
Final speed = -60 m/s (Since the the ball will now move in the opposite direction after hitting the bat, the speed is negative)
mass = 0.20 kg
Thus, we have
Impulse = 0.20 × (40m/s - (-60)m/s)
Impulse = 0.20 × 100 = 20 kg-m/s or 20 N.s
Answer:
0.68 seconds
Explanation:
Data provided in the question:
Mass of the box = 50 kg
Speed of the box = 1.0 m/s
Coefficient of friction, μ = 0.15
Now,
Force applied = μmg
Here,
g is the acceleration due to gravity = 9.8 m/s²
Thus,
F = 0.15 × 50 × 9.8
= 73.5 N
Also,
Force = Mass × Acceleration
thus,
73.5 N = 50 × a
or
a = 1.47 m/s²
After doubling the speed
Final speed = 2 × Initial speed
= 2 × 1 m/s
= 2 m/s
Also,
Acceleration = [change in speed] ÷ Time
or
1.47 = [ 2 - 1 ] ÷ Time
or
Time = 1 ÷ 1.47
or
Time = 0.68 seconds
<em>Kinetic (mechanical) energy</em>
A nice hot sunny day is what you want when using a solar oven.
Answer:
ac = 3.92 m/s²
Explanation:
In this case the frictional force must balance the centripetal force for the car not to skid. Therefore,
Frictional Force = Centripetal Force
where,
Frictional Force = μ(Normal Force) = μ(weight) = μmg
Centripetal Force = (m)(ac)
Therefore,
μmg = (m)(ac)
ac = μg
where,
ac = magnitude of centripetal acceleration of car = ?
μ = coefficient of friction of tires (kinetic) = 0.4
g = 9.8 m/s²
Therefore,
ac = (0.4)(9.8 m/s²)
<u>ac = 3.92 m/s²</u>
