A ball took 0.639s to hit the ground at distance 0.78m from the table. what is the ball's horizontal velocity when it left the table? Please help it’ll be greatly appreciated!!

It leaves the table traveling at 2.35 m/s and falls for 0.639 s.

Explanation:

This is a projectile motion problem. I will use the vertical motion to find the time in flight first, then I will calculate the launch speed. I think it is easiest this way.

Like any object that falls 2.00 m, the time required comes from

Δ

y

=

v

o

Δ

t

+

1

2

a

(

Δ

t

)

2

In this case,

v

o

=

0

,

Δ

y

=

−

2.00

m

(because it is falling) and

a

=

−

9.8

m

s

23

−

2.00

=

−

1

2

(

9.8

)

(

Δ

t

)

2

(

Δ

t

)

2

=

2.00

4.9

=

0.408

Δ

t

=

0.639

s

To travel 1.50 m in 0.639 s, the initial speed must have been

v

o

=

1.50

m

0.639

s

=

2.35

m

s

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation: