260 joules is hopefully right.
Answer:
<em>7 kgm/s or 7 Ns</em>
Explanation:
Since the velocity are perpendicular to each other, the impulses will also be perpendicular.
From newton's second law of motion,
Impulse = mass×velocity
I = mv............. Equation 1
For the horizontal,
I₁ = mv₁......... Equation 2
Given: m = 0.14 kg, v₁ = 40 m/s
Substitute into equation 2
I₁ = 40(0.14)
I₁ = 5.6 kgm/s
Also for the vertical,
I₂ = mv₂.............. Equation 3
Given: m= 0.14 kg, v₂ = 30 m/s
Substitute into equation 3
I₂ = 0.14(30)
I₂ = 4.2 kgm/s
Using Pythagoras to get the resultant impulse
I = √(I₁²+I₂²)................ Equation 4
Substitute the value of I₁ and I₂ into equation 4
I = √(5.6²+4.2²)
I = √(31.36+17.64)
I = √49
<em>I = 7 kgm/s or 7 Ns</em>
Answer:
The image is formed by a convex lens with the object at 2F.
- Image will be of same size as the object
- Image will be real and upside down.
Answer:
a) Andrea's initial momentum, 200 kg m/s
b) Andrea's final momentum, 0
c) Impulse, = - 200 Ns
d) The force that the seat belt exerts on Andrea, - 400 N
Explanation:
Given data,
The initial velocity of the car is, u = 40 m/s
The mass of Andrea, m = 50 kg
The time period of deceleration, a = 0.5 s
The final velocity of the car, v = 0
a) Andrea's initial momentum,
p = mu
= 50 x 40
= 200 kg m/s
b) Andrea's final momentum
P = mv
= 50 x 0
= 0 kg m/s
c) Impulse
I = mv - mu
= 0 - 200
= - 200 Ns
The negative sign indicated that the momentum is decreased.
d) The force that the seat belt exerts on Andrea
F = (mv - mu)t
= (0 - 200) / 0.5
= - 400 Ns
Hence,the force that the seat belt exerts on Andrea is, - 400 N
