Ouestion 1

On a hot summer day, a young girl swings on a rope above the local swimming hole. When she lets go of the rope her initial veloc

hodyreva [135]

Answer:

5.52 m

Explanation:

Using the equation;

Vy = Vo sin θ

Where; Vo = 2.25 m/s and θ = 35°

We get;

= 2.25 sin 35°

= 1.29 m/s

Thus; Vy = 1.29 m/s

But a = -9.81 m/s (against gravity)

t = 1.20 s and

y = Vyt + 1/2 at²

where y is the height above the water

= 1.29 × 1.2 + (1/2 × -9.81 × 1.2²)

= 1.548 + (-7.0632)

= - 5.5152 m

Thus; the height of the girl above the water is 5.52 m

4 0

3 years ago

A plate falls vertically to the floor and breaks up into three pieces, which slide along the floor. immediately after the impact

pshichka [43]

Refer to the diagram shown below.

Define the (x,y) plane as the horizontal plane of the floor.
There was no momentum in the (x,y) plane before the plate hit the floor.

Let the velocity components in the (x) and (y) directions of the 100 g mass be Vx and Vy respectively, and that the resultant velocity, V, makes an angle θ below the negative x-axis as shown.

Because momentum is conserved, therefore
100*Vx + 320*2 = 0
100Vx = -640
Vx = -6.4 m/s

100Vy + 355*1.5 = 0
100Vy = -532.5
Vy = -5.325 m/s

V = √[(-6.4)² + (-5.325)²] = 8.33 m/s
θ = tan⁻¹ (-5.325/-6.4) = 39.8°

Answer:
The direction is 39.8° below the negative x-axis
The speed is 8.33 m/s

8 0

3 years ago

Read 2 more answers

Assume that the ammeter in the figure below is removed and the current that flows through the 4.0Ω path, I3, is unknown. Determi

qaws [65]

The circuit is in parallel connection

Equivalent resistance = 1/Req = 1/R1 + 1/R2 + 1/R3

From the information given,

R1 = 5

R2 = 2

R3 = 4

1/Req = 1/5 + 1/2 + 1/4 = (4 + 10 + 5)/20 = 19/20

Req = 20/19 = 1.053 ohms

I = V/R

Given that V = 12,

Current flow through circuit = 12/1.053 = 11.4 A

I1 + I2 + I3 = 11.4

I1 = 12/5 = 2.4 A

I2 = 12/2 = 6 A

I3 = 12/4 = 3A

8 0

1 year ago

A force of 8,480 N is applied to a cart to accelerate it at a rate of 26.5 m/s2. What is the mass of the cart?

Anni [7]

F=ma
8480=26.5m
m=8480/26.5
m=320
The mass of the cart is 320kg.

8 0

3 years ago

Read 2 more answers

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanome

lina2011 [118]

Answer:

b) The star is moving away from us.

Explanation:

If an object moves toward us, the light waves it emits are compressed - the wavelength of the light will be shorter, making the light bluer. On the other hand, if an object moves away from us, the light waves are stretched, making it redder. If from laboratory measurements we know that a specific hydrogen spectral line appears at the wavelength of 121.6 nanometers (nm) and the spectrum of a particular star shows the same hydrogen line appearing at the wavelength of 121.8 nm, we can conclude that the star is moving away from npos, since the wavelength related to that star is more expanded.

7 0

3 years ago