Question

1. the speed of a cart is measured as 90.0 km/h. convert this speed to meters - per second (m/s). 90 km / m = 90,000 m, |
2. determine how many seconds are in one school day (7:45 to 2:29).

Explanation:

Step1: Convert km to m and h to s for speed conversion

We know that 1 km = 1000 m and 1 h=3600 s.
The speed is 90.0 km/h. To convert km to m, we multiply by 1000, and to convert h to s we divide by 3600. So the conversion formula is $v=\frac{90\times1000}{3600}$ m/s.
$v = 25$ m/s.

Step2: Calculate time - interval for school - day in seconds

First, convert 7:45 am to seconds from midnight. 7 hours = 7×3600 s = 25200 s, 45 minutes = 45×60 s=2700 s. So 7:45 am is 25200 + 2700=27900 s from midnight.
Next, convert 2:29 pm to seconds from midnight. 2 pm is 14 hours from midnight. 14 hours = 14×3600 s = 50400 s, 29 minutes = 29×60 s = 1740 s. So 2:29 pm is 50400+1740 = 52140 s from midnight.
The time - interval $\Delta t=52140 - 27900=24240$ s.

Answer:

1. The speed of the cart in m/s is 25 m/s.
2. The number of seconds in one school - day (7:45 to 2:29) is 24240 s.