What is charge measured in

Since the Sun has more mass, why do objects on earth not move closer to the Sun instead of staying put on Earth?

maw [93]

Answer:

Because the Earth has it's own gravity that keeps us put, and we also have the moon.

Explanation:

6 0

3 years ago

If f(x) = -x2+x-1 then value of f(f(2)) is

qaws [65]

Answer:

-13

Explanation:

Function

f(x) = -x² + x - 1

Solving

Substitute 2 in place of x
f(2) = -(2)² + 2 - 1
f(2) = -4 + 2 - 1
f(2) = -3
f(f(2)) = f(-3)
f(-3) = -(-3)² - 3 - 1
f(-3) = -9 - 3 - 1
f(f(2)) = -13

6 0

2 years ago

A 77.0 kg woman slides down a 42.6 m long waterslide inclined at 42.3. at the bottom, she is moving 20.3 m/s.how much work did f

zhuklara [117]

Answer:

5.791244495 KNm

Explanation:

The height h is given by, $h=42.6sin42.3^{o}$

Potential energy, PE is given by

PE=mgh where m is mass of the woman, g is acceleration due to gravity whose value is taken as $9.81 m/s^{2}$ and h is already given hence substituting 77 Kg for m we obtain

$PE=77*9.81*42.6sin42.3^{o}=21656.7095 Nm$

PE=21.6567095 KNm

We also know that Kinetic energy is given by $0.5mv^{2}$ where v is the velocity and substituting v for 20.3 we obtain

$KE=0.5*77*20.3^{2}=15865.465 Nm$

KE=15.865465 KNm

Friction work is the difference between PE and KE hence

Friction work=21.6567095 KNm-15865.465 Nm=5.791244495 KNm

8 0

3 years ago

A professional baseball player can throw the ball around 45 m/s if the distance between the pitcher and the batter is 18.39 m. H

svetlana [45]

Answer:

The time taken for the ball to get to the batter is 0.41 s.

Explanation:

Given;

initial velocity of the baseball, u = 45 m/s

horizontal distance between the pitcher and the batter, X = 18.39 m

The horizontal distance or range of a projectile is given as;

X = ut

where;

t is the time of flight

u is the initial velocity

t = X / u

t = 18.39 / 45

t = 0.41 s

Therefore, the time taken for the ball to get to the batter is 0.41 s.

6 0

3 years ago

n the railroad accident, a boxcar weighting 200 kN and traveling at 3 m/s on horizontal track slams into a stationary caboose we

USPshnik [31]

Answer:

ΔK = -6 10⁴ J

Explanation:

This is a crash problem, let's start by defining a system formed by the two trucks, so that the forces during the crash have been internal and the moment is preserved

initial instant. Before the crash

p₀ = m v₁ + M 0

final instant. Right after the crash

p_f = (m + M) v

p₀ = p_f

mv₁ = (m + M) v

v = $\frac{m}{m+M} \ v_1$

we substitute

v = $\frac{20}{20+40}$ 3

v = 1.0 m / s

having the initial and final velocities, let's find the kinetic energy

K₀ = ½ m v₁² + 0

K₀ = ½ 20 10³ 3²

K₀ = 9 10⁴ J

K_f = ½ (m + M) v²

K_f = ½ (20 +40) 10³ 1²

K_f = 3 10⁴ J

the change in energy is

ΔK = K_f - K₀

ΔK = (3 - 9) 10⁴

ΔK = -6 10⁴ J

The negative sign indicates that the energy is ranked in another type of energy

7 0

3 years ago