Answer:
The initial velocity was U=22.14m/s
Explanation:
Step one :
Applying the third equation of motion
v² = u²+ 2as
Where v= Final velocity
U =initial velocity
a= acceleration due to gravity
S= distance or displacement
Step two :
V= 0
a= 9.81m/s²
S=25m
U=?
Step three :
Substituting into the equation we have
0²=U²+2*9.81*25
0=U²+490.5
U²=-490.5
U=√490.5
U=22.14m/s
Answer:
<em>The force required is 3,104 N</em>
Explanation:
<u>Force</u>
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = ma
Where a is the acceleration of the object.
On the other hand, the equations of the Kinematics describe the motion of the object by the equation:
Where:
vf is the final speed
vo is the initial speed
a is the acceleration
t is the time
Solving for a:
We are given the initial speed as vo=20.4 m/s, the final speed as vf=0 (at rest), and the time taken to stop the car as t=7.4 s. The acceleration is:
The acceleration is negative because the car is braking (losing speed). Now compute the force exerted on the car of mass m=1,126 kg:
F= 3,104 N
The force required is 3,104 N
Answer: The level of CO2 has risen.
Explanation:
From the table shown, we can see that the quantity of CO₂ in the atmosphere has steadily risen since the year 1960 going from 317 CO₂PPM in that year to 390 CO₂PPM in 2010.
This is a cause for alarm because with so much carbon dioxide in the atmosphere, there will be an even greater greenhouse effect that will contribute to global warming.
Answer:
a. the core will spin faster.
Explanation:
By law of conservation of angular momentum
(mvR)i= (mvR)f
m= mass of star
v= speed of star
R= radius of star
i= initial
f= final
since, size(R) of the star is reduced by factor of 10,000 and mass remains the same, the velocity must increase by the same factor to keep the angular momentum conserved.
Hence, a. the core will spin faster.
Answer:
A: Sound waves produce an echo
Explanation:
because the cup is a hard smooth surface you can hear the voice
