A rifle fires. The bullet flies forward at hundreds of meters per second, while the rifle only kicks back a little against the shooter's shoulder.
Yet the third law says the bullet and the rifle felt equal-magnitude forces.
Equal forces do not mean equal responses. Each object answers with its own acceleration, and a = F_net/m says by exactly how much.
While the rifle fires, the bullet and the rifle feel equal-magnitude forces in opposite directions.
A loaded shopping cart and an empty one roll into each other. Beth says: 'During the bump, the force on the empty cart and the force on the loaded cart have the same magnitude.' Is she correct?
Give the pair numbers. The force on each is 200 N. The bullet's mass is 0.010 kg. The rifle's mass is 4.0 kg.
Each object's acceleration comes from a = F_net/m, applied to that object alone.
The bullet: a = 200 ÷ 0.010 = 20000 m/s², forward.
The rifle: a = 200 ÷ 4.0 = 50 m/s², backward.
Same force magnitude, 400 times the mass, one four-hundredth the acceleration. The smaller mass always takes the larger acceleration.
While an arrow leaves a bow, the arrow and the bowstring exert equal-magnitude forces on each other. Which object takes the larger acceleration?
The trade reads straight off the equation: with F_net fixed, doubling the mass halves the acceleration, and a tenth of the mass means ten times the acceleration.
Two ice skaters, 48 kg and 80 kg, press their palms together and move apart. While their palms exert 120 N forces on each other, calculate the 48 kg skater's acceleration.
Write down the values in the question:
F_net = 120 N
m = 48 kg
a = ?
Write down the equation:
a = F_net/m
Substitute in the values:
a = 120 ÷ 48
Simplify:
a = 2.5 m/s²
The 48 kg skater's acceleration is 2.5 m/s², away from the other skater.
The same pair: calculate the 80 kg skater's acceleration, and compare.
Write down the values in the question:
F_net = 120 N
m = 80 kg
a = ?
Write down the equation:
a = F_net/m
Substitute in the values:
a = 120 ÷ 80
Simplify:
a = 1.5 m/s², the opposite way
1.5 m/s², the opposite way. The forces are equal; the more massive skater takes the smaller acceleration.
Tilda (55 kg) and a loaded luggage cart (22 kg) press apart on a smooth floor. While the force between them is 110 N, enter the cart's acceleration in m/s².
During a collision, a bowling ball and a pin exert 180 N forces on each other. The pin's mass is 2.0 kg. Enter the pin's acceleration in m/s².
Object A has five times the mass of object B. While the two exert equal-magnitude forces on each other, how does A's acceleration compare with B's?
A city bus collides with a parked compact car. Which statement is correct?