True or false around 250 million year ago, all the continents were joined in one landmass, called Cambria

Which of the following objects is NOT accelerating?

MatroZZZ [7]

Answer:

A Bicycle

Explanation:

A Space shuttle accelerating because the Earth pulls on it through the gravitational force.

A Truck is accelerating because acceleration is necessary for an object to change direction.

A car is accelerating because it is speeding up unexpectedly?????

4 0

3 years ago

How long does for one rotation of earth

stellarik [79]

Answer: 24 hours

Explanation: One day is one rotation of the Earth, but it takes the earth 365 days to do one revolution or one year

8 0

3 years ago

A bowling ball (mass = 7.2 kg, radius = 0.11 m) and a billiard ball (mass = 0.38 kg, radius = 0.028 m) may each be treated as un

Semenov [28]

Answer:

Explanation:

Given that

Mass of bowling ball M1=7.2kg

The radius of bowling ball r1=0.11m

Mass of billiard ball M2=0.38kg

The radius of the Billiard ball r2=0.028m

Gravitational constant

G=6.67×10^-11Nm²/kg²

The magnitude of their distance apart is given as

r=r1+r2

r=0.028+0.11

r=0.138m

Then, gravitational force is given as

F=GM1M2/r²

F=6.67×10^-11×7.2×0.38/0.138²

F=9.58×10^-9N

The force of attraction between the two balls is

F=9.58×10^-9N

3 0

3 years ago

The position function of a particle is given by s=2t3−3t2−63t,t⩾0.s=2t3−3t2−63t,t⩾0. where ss is measured in meters and tt in se

Kisachek [45]

Answer:

$t=5.72\ s$

Explanation:

Given:

the displacement as the function of time:

$s=2t^3-3t^2-63t$

here time is in seconds and the displacement in meters.

Now we differentiate this eq. of displacement to get the equation of velocity:

$v=\frac{d}{dt}(s) \\v=6t^2-6t-63$

According to given the velocity is $99\ m.s^{-1}$ at some time:

$99=6t^2-6t-63$

$6t^2-6t-162=0$

$t=5.72\ s$ & is the only time for (t>=0) instances when the particle will have a velocity of $99\ m.s^{-1}$ but in the opposite direction.

8 0

4 years ago

As shown in the figure below, a bullet is fired at and passes through a piece of target paper suspended by a massless string. Th

NikAS [45]

Answer:

M = 0.730*m

V = 0.663*v

Explanation:

Data Given:

$v_{bullet, initial} = v\\v_{bullet, final} = 0.516*v\\v_{paper, initial} = 0\\v_{paper, final} = V\\mass_{bullet} = m\\mass_{paper} = M\\Loss Ek = 0.413 Ek$

Conservation of Momentum:

$P_{initial} = P_{final}\\m*v_{i} = m*0.516v_{i} + M*V\\0.484m*v_{i} = M*V .... Eq1$

Energy Balance:

$\frac{1}{2}*m*v^2_{i} = \frac{1}{2}*m*(0.516v_{i})^2 + \frac{1}{2}*M*V^2 + 0.413*\frac{1}{2}*m*v^2_{i}\\\\0.320744*m*v^2_{i} = M*V^2\\\\M = \frac{0.320744*m*v^2_{i} }{V^2} ....... Eq 2$

Substitute Eq 2 into Eq 1

$0.484*m*v_{i} = \frac{0.320744*m*v^2_{i} }{V^2} *V \\0.484 = 0.320744*\frac{v_{i} }{V} \\\\V = 0.663*v_{i}$

Using Eq 1

$0.484m*v_{i} = M* 0.663v_{i}\\\\M = 0.730*m$

7 0

3 years ago