Answer:
Explanation:
We must separate the motion into two parts, the first when the rocket's engines is on and the second when the rocket's engines is off. So, we need to know the height (
) that the rocket reaches while its engine is on and we need to know the distance (
) that it travels while its engine is off.
For solving this we use the kinematic equations:
In the first part we have:
and the final speed is:
In the second part, the final speed of the first part it will be the initial speed, and the final speed is zero, since gravity slows it down the rocket.
So, we have:
The sum of these heights will give us the total height, which is known:
This is the time that its needed in order for the rocket to reach the required altitude.
i think its a, good luck on your test
The entire range of anything is called its spectrum.
For em wavelengths, it's the electromagnetic spectrum.
Answer:
The correct option is;
B. Subtract vectors A from C; 
= 12 N
Explanation:
The given parameters are;
The weight of the dresser = 250 N
The force applied by the man = 20 N = C
The frictional force provided by the carpet = 8 N = The component of the weight resisting motion = A
Therefore, the net force tending to put the dresser in motion, , is given as follows;
= The force applied by the man, C - The frictional force provided by the carpet which is the component of the weight resisting motion, A
= C - A = 20 N - 8 N = 12 N
= 12 N
The resulting net force, = 12 N.
Answer:
The minimum total speed is 11.2km/s
Explanation:
We are been asked to find the escape velocity.
Escape velocity is defined as the minimum initial velocity that will take a body(projectile)away above the surface of a planet(earth) when it's projected vertically upwards.
The formula to calculate the escape velocity is Ve = √2gR
For the earth g = 9.8m/s2 , R = 6.4*10^6
Substituting into the equation Ve = √2*9.8*6.4*10^6 = 11.2*10^3m/s
=11.2km/s
