Vi=15m/s
vf=20m/s
d=50m
a=(vf²-vi²)/2d
average acceleration= 1.75m/s
Answer:
The ground exerts an equal force on the golf ball
Explanation:
Third's Newton Law states that:
"When an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A".
In this problem, object A is the golf ball while object B is the ground, so we can say that:
- the golf ball exerts a force on the ground
- the ground exerts an equal and opposite force on the golf ball
Answer:
-20000 kgm/s
Explanation:
Impulse: This can be defined as the product of the mass of a body and its change in velocity. The S.I unit of impulse is kgm/s.
Mathematically, impulse can be expressed as
I = m(v-u).............. Equation 1.
Where I = impulse applied to the car to bring it to rest, m = mass of the car, u = initial velocity of the car, v = final velocity of the car.
Given: m = 1000 kg, u = 20 m/s, v = 0 m/s ( to rest)
Substitute into equation 1
I = 100(0-20)
I = 1000(-20)
I = -20000 kgm/s
Hence the impulse applied to the car to bring it to rest = -20000 kgm/s
Answer:
Explanation:
Let the velocity be v
Total energy at the bottom
= rotational + linear kinetic energy
= 1/2 Iω² + 1/2 mv² ( I moment of inertia of shell = mr² )
= 1/2 mr²ω² + 1/2 mv² ( v = ω r )
= 1/2 mv² +1/2 mv²
= mv²
mv² = mgh ( conservation of energy )
v² = gh
v = √gh
= √9.8 x 1.8
= 4.2 m /s
Answer:
4
Explanation:
In order for the current to continue flowing through the circuit (and for the bulbs to continue shining), there must be a closed path containing the battery where current can flow. Let's see the effect of removing each bulb on the circuit:
- 1: when removing bulb 1 only, the current can still flow through the path battery-bulb 3- bulb 4
- 2: when removing bulb 2 only, the current can still flow through the path battery-bulb 3- bulb 4
- 3: when removing bulb 3 only, the current can still flow through the path battery-bulb 1-bulb 2- bulb 4
- 4: when removing bulb 4 only, the current can no longer flow. In fact, there is no closed path that contains the battery now, so the current will not flow and all the bulbs will stop shining.
