Answer:
The average acceleration during the 6.0 s interval was -27 m/s².
Explanation:
Hi there!
The average acceleration is defined as the change in velocity over time:
a = Δv/t
Where:
a = acceleration.
Δv = change in velocity = final velocity - initial velocity
t = elapsed time
The change in velocity will be:
Δv = final velocity - initial velocity
Δv = -74 m/s - 87 m/s = -161 m/s
(notice the negative sign of the velocity that is in opposite direction to the direction considered positive)
Then the average acceleration will be:
a = Δv/t
a = -161 m/s / 6.0 s
a = -27 m/s²
The average acceleration during the 6.0 s interval was -27 m/s².
Answer:

Explanation:
Given that,
The energy of the microwave oven is
.
We need to find the wavelength of these photons.

The energy of a wave is given by :

Put all the values,

So, the wavelength of these photon is
.
Answer:
KE = 1.75 J
Explanation:
given,
mass of ball, m₁ = 300 g = 0.3 Kg
mass of ball 2, m₂ = 600 g = 0.6 Kg
length of the rod = 40 cm = 0.4 m
Angular speed = 100 rpm= 
=10.47\ rad/s
now, finding the position of center of mass of the system
r₁ + r₂ = 0.4 m.....(1)
equating momentum about center of mass
m₁r₁ = m₂ r₂
0.3 x r₁ = 0.6 r₂
r₁ = 2 r₂
Putting value in equation 1
2 r₂ + r₂ = 0.4
r₂ = 0.4/3
r₁ = 0.8/3
now, calculation of rotational energy




KE = 1.75 J
the rotational kinetic energy is equal to 1.75 J
Answer:
The spring force constant is
.
Explanation:
We are told the mass of the ball is
, the height above the spring where the ball is dropped is
, the length the ball compresses the spring is
and the acceleration of gravity is
.
We will consider the initial moment to be when the ball is dropped and the final moment to be when the ball stops, compressing the spring. We supose that there is no friction so the initial mechanical energy
is equal to the final mechanical energy
:

Initially there is only gravitational potential energy because the force of the spring isn't present and the speed is zero. In the final moment there is only elastic potential energy because the height is zero and the ball has stopped. So we have that:

If we manipulate the equation we have that:




Answer:
the total momentum is 8 .2 kg m/s in north direction.
Explanation:
given,
mass(m₁) 3.00 kg, moving north at v₁ = 3.00 m/s
mass(m₂) 4.00 kg, moving south at v₂ = 3.70 m/s
mass(m₃) 7.00 kg, moving north at v₃ = 2.00 m/s
north as the positive axis
south as the negative axis
now
total momentum = m₁v₁ + m₂ v₂ + m₃ v₃
total momentum = 3 x 3 - 4 x 3.7 + 7 x 2
= 9 - 14.8 + 14
= 8 .2 kg m/s
hence, the total momentum is 8 .2 kg m/s in north direction.