Answer:
a) Yes
b) 7 rad/s
c) 0.01034 J
Explanation:
a)
Yes the angular momentum of the block is conserved since the net torque on the block is zero.
b)
m = mass of the block = 0.0250 kg
w₀ = initial angular speed before puling the cord = 1.75 rad/s
r₀ = initial radius before puling the cord = 0.3 m
w = final angular speed after puling the cord = ?
r = final radius after puling the cord = 0.15 m
Using conservation of angular momentum
m r₀² w₀ = m r² w
r₀² w₀ = r² w
(0.3)² (1.75) = (0.15)² w
w = 7 rad/s
c)
Change in kinetic energy is given as
ΔKE = (0.5) (m r² w² - m r₀² w₀²)
ΔKE = (0.5) ((0.025) (0.15)² (7)² - (0.025) (0.3)² (1.75)²)
ΔKE = 0.01034 J
Answer:
v = 66.4 m/s
Explanation:
As we know that plane is moving initially at speed of
now we have
now in Y direction we can use kinematics
since there is no acceleration in x direction so here in x direction velocity remains the same
so we will have
Answer:
Time, t = 0.57 hours
Explanation:
It is given that,
Speed of the school bus, v = 35 mi/hr
Distance covered by the bus, d = 20 miles
We need to find the time taken by the bus to get to school. Time taken by the bus is given by :
t = 0.57 hours
So, the time taken by the bus to reach school is 0.57 hours. Hence, this is the required solution.
Acceleration is given by:
where
v is the final velocity
u is the initial velocity
t is the time interval
Let's apply the formula to the different parts of the problem:
A) 
Let's convert the quantities into SI units first:
t = 4.0 min = 240 s
So the acceleration is
B) 
As before, let's convert the quantities into SI units first:
t = 94 s
So the acceleration is
C) 
For this part we have to use a different formula:
where we have
v = 0 is the final velocity
u = 89.2 m/s is the initial velocity
a is the acceleration
d = 75 m is the distance covered
Solving for a, we find
<span>1. They’re invisible - RADIO WAVES
2. They have colors. - VISIBLE LIGHT WAVES
3. They’re used to learn about dust and gas clouds. - BOTH
4. They can travel in a vacuum. </span> - BOTH<span>
5. They’re used to find the temperature of stars. </span>- VISIBLE LIGHT WAVES<span>
6. They have energy. </span> - BOTH
